You still did not answer my question. What device are you trying to control, not what code are you trying to enter into the RCOIR remote? The reason I ask is there might be a spreadsheet or something on this site that would prevent you from having to do the following process for every code you need as is illustrated below.

Take the code you have and go to the Yamaha site referenced by you above. Put in your NEC code to Generate the Long form of Pronto Hex IR format. Then use the Pronto Hex importer which is in 'Beta' in the screen shot above.

For example:
0x20DE 0x906F

On the site enter 20DE906F and press generate. you will then get a long version of this code. You can then plug that into the software Beta Pronto Converter.

Don't use WINLIRC_NEC1 format.

If you can successfuly get the power code entered and it does not work then the issue may be that you have a code that is not for your equipment. Again please answer my first question so we can help find you the right set of codes to use.